/// <inheritdoc />
public override void Read(NatReader reader)
{
base.Read(reader);
reader.ReadUInt16(); // reserved
RequestedLifetime = reader.ReadTimeSpan();
ClientAddress = reader.ReadIPv6Address();
}
/// <inheritdoc />
public override void Read(NatReader reader)
{
Version = reader.ReadByte();
var opcode = reader.ReadByte();
Opcode = (Opcode)(opcode & 0x7f);
IsResponse = (opcode & 0x80) == 0x80;
}
/// <inheritdoc />
public override void Read(NatReader reader)
{
base.Read(reader);
reader.ReadByte(); // reserved
ResultCode = reader.ReadByte();
Lifetime = reader.ReadTimeSpan();
EpochTime = reader.ReadTimeSpan();
var _ = reader.ReadBytes(reserved2.Length);
}
/// <inheritdoc />
public override void Read(NatReader reader)
{
base.Read(reader);
Nonce = reader.ReadBytes(NonceLength);
Protocol = (ProtocolType)reader.ReadByte();
reader.ReadByte(); // reserved 24 bits (3 bytes)
reader.ReadByte();
reader.ReadByte();
InternalPort = reader.ReadUInt16();
AssignedExternalPort = reader.ReadUInt16();
AssignedExternalAdddress = reader.ReadIPv6Address();
}
/// <inheritdoc />
public override void Read(NatReader reader)
{
}
/// <summary>
/// Create a message from the specified datagram.
/// </summary>
/// <param name="datagram">
/// The byte array containing the message.
/// </param>
/// <returns>
/// A <see cref="Message"/> that represents the <paramref name="datagram"/>.
/// </returns>
public static Message Create(byte[] datagram)
{
if (datagram == null || datagram.Length < 4)
{
throw new InvalidDataException("NAT-PCP datagram must be at least 4 bytes.");
}
using (var ms = new MemoryStream(datagram, false))
{
// Get the type of message.
var reader = new NatReader(ms);
var header = new Message();
header.Read(reader);
Message msg = null;
if (header.IsResponse)
{
switch (header.Opcode)
{
case Opcode.Announce:
msg = new Response(); // no specific response data
break;
case Opcode.Map:
msg = new MapResponse();
break;
case Opcode.Peer:
msg = new Response(); // TODO
break;
default:
throw new NotSupportedException($"NAT-PCP response with opcode {header.Opcode}.");
}
}
else
{
switch (header.Opcode)
{
case Opcode.Announce:
msg = new AnnounceRequest();
break;
case Opcode.Map:
msg = new MapRequest();
break;
case Opcode.Peer:
msg = new PeerRequest();
break;
default:
throw new NotSupportedException($"NAT-PCP request with opcode {header.Opcode}.");
}
}
// Read the message data.
reader.Position = 0;
msg.Read(reader);
return(msg);
}
}
